Pressure vessels having an inlet and outlet have been used for a variety of purposes. Many of these pressure vessels are operated either in a vertical position or a horizontal position. In the vertical position, the axis of the pressure vessel is orientated generally vertically with respect to ground level, and in the horizontal position, the axis of the pressure vessel is generally disposed horizontally with respect to ground level.
In the oil and gas industry, pressure vessels are sometimes used to separate sand or other solids from fluids such as hydrocarbons produced from a wellhead. In some cases, the pressure vessels are operated in the vertical position and, in others, they are operated in the horizontal position.
Furthermore, such pressure vessels used in the oil and gas industry are typically transported to be erected at the well site, and thus employ various assemblies used to facilitate such transport and erection. For example, one design that has been employed utilizes a mobile rig having a rig transporter comprising a motorized unit, a masked assembly, a pivotal connection to the mass assembly with respect to the rig transporter. At least one hydraulic arm is pivotally mounted to the rig transporter and the masked assembly operable to move the masked to an upright position and for lowering the masked to a substantially horizontal position for transportation.